CNN Suspect -- Detained by LAPD

4/7/2011 8:20 PM PDT

CNN Suspect -- Detained by LAPD

The employees at the CNN building in L.A. can rest easy -- because the man who allegedly threatened to shoot staff members earlier this week was detained by the LAPD last night ... TMZ has learned.

Law enforcement sources tell TMZ ... the man was NOT arrested -- but authorities did place him on a 5150 psychological hold -- which gives medical personnel 72 hours to evaluate his mental state. 

As we first reported, the suspect's father called 911 on Tuesday, claiming his son was threatening to shoot someone ... and mentioned the CNN building.

The building -- located on Sunset Blvd. -- has been on lockdown ever since.